It is known to measure operating parameters within a chip, insofar as temperature is concerned. For example, the Intel Pentium 4 Processor includes an on-die thermal diode, as described by Intel in the Data Sheet and the Thermal Design Guidelines for this chip. The Pentium 4 uses a dedicated off-chi connection for an analogue output signal which indicates temperature.
When the Pentium 4 thermal diode senses excessive temperature, a signal is made externally available by the off-chip connection. External circuitry then causes the system clock to be intermittently frozen. This decreases the average clock rate, which decreases the average power dissipation, which decreases the temperature.
This design has several significant disadvantages, among which is that each processor must be individually calibrated. Also, this analogue design requires fabrication of both analogue and digital devices on the same chip, using the same production line. This places extra requirements on process control, and may add extra processing costs.
Moreover, the Pentium 4 design does not enable software monitoring of temperature and does not enable software control of the response to the temperature measurement.
Further, the prior art is solely concerned with temperature when monitoring internal physical parameters. It is now apparent that monitoring of other internal physical parameters, such as power consumption, will also be necessary to advance the semiconductor art.
What is needed is a means for making measured operating parameters available to the system software so as to permit the system to respond in a manner with all the sophistication that software logic makes available. What is also needed is to use this software accessibility to eliminate the need for factory calibration and to eliminate the need for dedicated connections.